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Monday, November 07, 2011

What are natural units?

I noticed that I confused some readers by referring to temperatures in GeV and distances as the inverse of an energy. 15 years ago, when I first learned about natural units, it seemed really fishy to me. Now Stefan has to remind me on occasion that a second is not a distance, and an entropy is not dimensionless. Since I've experimented lately with some new software, I put together a few slides on the use of natural units and youtubed them.

At 3:20min it should be 5000K, not 500K, sorry about that. At 3:30min, Lara tried to eat the keyboard.

I made the slides with Powerpoint. They have much improved the equation editor. One can also record the audio with Powerpoint and set a timing for the text to appear. You can then export it as some windows movie or so. I imported that movie with with Corel's Videostudio, edited it somewhat and exported as mpg. It was really straight forward. I first tried to make it all with the Videostudio, but the equations I would have to either write by hand or include as an image, so I would have needed another software anyway. Best,

Excellent question :o) I first wanted to include derivatives, fields, mass dimensions of operators etc. But then it got too long and also more technical. Maybe I make a follow-up video at some point. Best,

Certainly a clear explanation regarding natural units as one is brought to understand they allow for examination of the qualifiers without need of being distracted by the quantifiers and thus how can anyone not consider qualities as something objectively analyzable. It’s also nice to discover that Lara is so interested to as to be literally cutting the teeth on it.

Cool, first time to hear your voice, Bee. Note that the program of converting to completely natural units of the Planck scale need not always use G. The natural charge is constructed from h and c (and is inexplicably around 11.7 times actual charge quantum e.)

Planck units go farther than natural units by omitting even the mass scale. Eg in natural units, the Schwarzschildradius is 2M/m_p^2. In Planck units it's 2M. Planck Units are frequently used in the gr-qc community and I find them terribly confusing. Best,